1. Field of the Invention
The present invention relates to the field of display technology, and in particular to a method for manufacturing a flexible display device and a flexible display device so manufactured.
2. The Related Arts
Organic light emitting display (OLED) has various advantages, such as being self-luminous, low driving voltage, high light emission efficiency, short response time, high definition and contrast, approximately 180° view angle, wide temperature range of applications, and being capable of flexible displaying and large area full color displaying, and thus has an increasingly widened application and is considered a display device having the greatest development potential in the business. With the progress of OLED technology, the advantage of the OLED for being flexible provides the development of a flexible OLED display device, which due to the characteristics of being flexible and easy to carry, is now a major sector of research and development of the field of display technology.
Base plates that are currently usable in a flexible OLED display device include thin stainless steel plates, polymeric plastics, and soft glass sheets. Among them, the thin stainless steel plates have high surface roughness and must involve a planarization layer in the application thereof, making the cost high. The polymeric plastic sheets and the soft glass sheets are the current hot spots of research study. For a manufacturing process of a flexible OLED display device, intact separation of a flexible base plate and a glass carrier is a key technique of the manufacturing process.
As shown in FIG. 1, a schematic view is provided for illustrating a conventional structure of a blank plate of a flexible base plate. The blank plate of a flexible base plate comprises a carrier plate 10, a release layer 20 formed on the carrier plate 10, a bonding layer 30 formed on the release layer 20, and a soft glass plate 40 bonded to the bonding layer 30. In manufacturing a flexible display device, it also needs to make a display structure unit and a package structure unit on the soft glass plate 40 and finally, a laser based separation process is applied to separate the flexible display device from the carrier plate 10.
Compared to a plastic film, the soft glass plate possesses electric performance similar to that of rigid glass and has certain capability of resisting moisture and oxygen. However, the above-described known technique suffers certain problems. The conventional OLED display devices often use low-temperature poly-silicon (LTPS) thin-film transistor (TFT) technology or oxide semiconductor (OS) TFT technology and thus, in an excimer laser annealing (ELA) process, a high temperature operation and a laser based separation operation inevitably lead to an increase of the brittleness of the soft glass plate, making cracking generated on and expanded through the soft glass plate thereby affecting the performance of the display structure unit arranged on a top of the soft glass plate and lowering down the product yield rate.